Go back to nvidia-304 because it contains better chipset
support for our current situation (probably).  It would be nice
to get nvidia-304 and nvidia-331 to co-exist somehow, but we
do not know yet how to do that it a nice way.
Link /usr/share/icons/Faenza/apps/24/evolution.png to
evolution-calendar.png so that calendar app in panel
has some icon (Faenza icon theme needs some updating I guess).